ZyXEL Communications P-871H Series, Руководство пользователя

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P-871H Series User’s Guide
38 Chapter 5 Basic Setting
Figure 13 Switch Setup
The following table describes the labels in this screen.
Table 10 Switch Setup
LABEL DESCRIPTION
VLAN Type Choose 802.1Q or Port Based . The VLAN Setup screen changes depending on
whether you choose 802.1Q VLAN type or Port Based VLAN type in this screen.
See Chapter 6 on page 43 for more information.
Priority Queue Assignment
IEEE 802.1p defines up to eight separate traffic types by inserting a tag into a MAC-layer frame that
contains bits to define class of service. Frames without an explicit priority tag are given the default
priority of the ingress port. Use the next two fields to configure the priority level-to-physical queue
mapping.
The Prestige has four physical queues that you can map to the 8 priority levels. On the Prestige, traffic
assigned to higher index queues gets through faster while traffic in lower index queues is dropped if the
network is congested.
Priority Level (The following descriptions are based on the traffic types defined in the IEEE 802.1d
standard (which incorporates the 802.1p).
Level 7 Typically used for network control traffic such as router configuration messages.
Level 6 Typically used for voice traffic that is especially sensitive to jitter (jitter is the
variations in delay).
Level 5 Typically used for video that consumes high bandwidth and is sensitive to jitter.
Level 4 Typically used for controlled load, latency-sensitive traffic such as SNA (Systems
Network Architecture) transactions.
Level 3 Typically used for “excellent effort” or better than best effort and would include
important business traffic that can tolerate some delay.
Level 2 This is for “spare bandwidth”.
Level 1 This is typically used for non-critical “background” traffic such as bulk transfers that
are allowed but that should not affect other applications and users.
IGMP Snooping Select the Active checkbox to enable IGMP snooping have group multicast traffic
only forwarded to ports that are members significantly reducing multicast traffic
passing through your Prestige. See Section 5.4 on page 37 for more information on
IGMP snooping.